On 3/25/23 06:31, David Gow wrote:
Many uses of the KUnit resource system are intended to simply defer calling a function until the test exits (be it due to success or failure). The existing kunit_alloc_resource() function is often used for this, but was awkward to use (requiring passing NULL init functions, etc), and returned a resource without incrementing its reference count, which -- while okay for this use-case -- could cause problems in others.
Instead, introduce a simple kunit_defer() API: a simple function (returning nothing, accepting a single void* argument) can be scheduled to be called when the test exits. Deferred functions are called in the opposite order to that which they were registered.
This is implemented as a resource under the hood, so the ordering between resource cleanup and deferred functions is maintained.
Signed-off-by: David Gow davidgow@google.com
include/kunit/resource.h | 87 +++++++++++++++++++++++++++++++ lib/kunit/resource.c | 110 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 197 insertions(+)
diff --git a/include/kunit/resource.h b/include/kunit/resource.h index cf6fb8f2ac1b..6c4728ca9237 100644 --- a/include/kunit/resource.h +++ b/include/kunit/resource.h @@ -387,4 +387,91 @@ static inline int kunit_destroy_named_resource(struct kunit *test, */ void kunit_remove_resource(struct kunit *test, struct kunit_resource *res); +typedef void (*kunit_defer_function_t)(void *ctx);
+/**
- kunit_defer() - Defer a function call until the test ends.
- @test: Test case to associate the deferred function with.
- @func: The function to run on test exit
- @ctx: Data passed into @func
- @internal_gfp: gfp to use for internal allocations, if unsure, use GFP_KERNEL
- Defer the execution of a function until the test exits, either normally or
- due to a failure. @ctx is passed as additional context. All functions
- registered with kunit_defer() will execute in the opposite order to that
- they were registered in.
- This is useful for cleaning up allocated memory and resources.
- RETURNS:
Is this intentional? Unless I'm mistaken the kernel-doc return value specifier is 'Return:'.
- An opaque "cancellation token", or NULL on error. Pass this token to
- kunit_defer_cancel() in order to cancel the deferred execution of func().
- */
+void *kunit_defer(struct kunit *test, kunit_defer_function_t func,
void *ctx, gfp_t internal_gfp);+/**
- kunit_defer_cancel_token() - Cancel a deferred function call.
- @test: Test case the deferred function is associated with.
- @cancel_token: The cancellation token returned by kunit_defer()
- Prevent a function deferred using kunit_defer() from executing when the
- test ends.
- Prefer using this to kunit_defer_cancel() where possible.
- */
+void kunit_defer_cancel_token(struct kunit *test, void *cancel_token);
+/**
- kunit_defer_trigger_token() - Run a deferred function call immediately.
- @test: Test case the deferred function is associated with.
- @cancel_token: The cancellation token returned by kunit_defer()
- Execute a deferred function call immediately, instead of waiting for the
- test to end.
- Prefer using this to kunit_defer_trigger() where possible.
- */
+void kunit_defer_trigger_token(struct kunit *test, void *cancel_token);
+/**
- kunit_defer_cancel() - Cancel a matching deferred function call.
- @test: Test case the deferred function is associated with.
- @func: The deferred function to cancel.
- @ctx: The context passed to the deferred function to trigger.
- Prevent a function deferred via kunit_defer() from executing at shutdown.
- Unlike kunit_defer_cancel_token(), this takes the (func, ctx) pair instead of
- the cancellation token. If that function/context pair was deferred multiple
- times, only the most recent one will be cancelled.
- Prefer using kunit_defer_cancel_token() to this where possible.
- */
+void kunit_defer_cancel(struct kunit *test,
kunit_defer_function_t func,void *ctx);+/**
- kunit_defer_trigger() - Run a matching deferred function call immediately.
- @test: Test case the deferred function is associated with.
- @func: The deferred function to trigger.
- @ctx: The context passed to the deferred function to trigger.
- Execute a function deferred via kunit_defer() immediately, rather than when
- the test ends.
- Unlike kunit_defer_trigger_token(), this takes the (func, ctx) pair instead of
- the cancellation token. If that function/context pair was deferred multiple
- times, it will only be executed once here. The most recent deferral will
- no longer execute when the test ends.
- kunit_defer_trigger(test, func, ctx);
- is equivalent to
- func(ctx);
- kunit_defer_cancel(test, func, ctx);
- Prefer using kunit_defer_trigger_token() to this where possible.
- */
+void kunit_defer_trigger(struct kunit *test,
kunit_defer_function_t func,void *ctx);diff --git a/lib/kunit/resource.c b/lib/kunit/resource.c index c414df922f34..0d0c48054d45 100644 --- a/lib/kunit/resource.c +++ b/lib/kunit/resource.c @@ -77,3 +77,113 @@ int kunit_destroy_resource(struct kunit *test, kunit_resource_match_t match, return 0; } EXPORT_SYMBOL_GPL(kunit_destroy_resource);
+struct kunit_defer_ctx {
- kunit_defer_function_t func;
- void *ctx;
+};
+static void __kunit_defer_free(struct kunit_resource *res) +{
- struct kunit_defer_ctx *defer_ctx = (struct kunit_defer_ctx *)res->data;
- defer_ctx->func(defer_ctx->ctx);
- kfree(res->data);
+}
+void *kunit_defer(struct kunit *test, kunit_defer_function_t func,
void *ctx, gfp_t internal_gfp)+{
- struct kunit_resource *res;
- struct kunit_defer_ctx *defer_ctx;
- KUNIT_ASSERT_NOT_NULL_MSG(test, func, "Tried to defer a NULL function!");
- res = kzalloc(sizeof(*res), internal_gfp);
- if (!res)
return NULL;- defer_ctx = kzalloc(sizeof(*defer_ctx), internal_gfp);
- if (!defer_ctx)
goto free_res;- defer_ctx->func = func;
- defer_ctx->ctx = ctx;
- res->should_kfree = true;
- __kunit_add_resource(test, NULL, __kunit_defer_free, res, defer_ctx);
- return (void *)res;
+free_res:
- kfree(res);
- return NULL;
+}
+void kunit_defer_cancel_token(struct kunit *test, void *cancel_token) +{
- struct kunit_resource *res = (struct kunit_resource *)cancel_token;
- /* Remove the free function so we don't run the deferred function. */
- res->free = NULL;
- kunit_remove_resource(test, res);
+}
+void kunit_defer_trigger_token(struct kunit *test, void *cancel_token) +{
- struct kunit_resource *res = (struct kunit_resource *)cancel_token;
- /* Removing the resource should trigger the res->free function. */
- kunit_remove_resource(test, res);
+}
+static bool __kunit_defer_match(struct kunit *test,
struct kunit_resource *res, void *match_data)+{
- struct kunit_defer_ctx *match_ctx = (struct kunit_defer_ctx *)match_data;
- struct kunit_defer_ctx *res_ctx = (struct kunit_defer_ctx *)res->data;
- /* Make sure this is a free function. */
- if (res->free != __kunit_defer_free)
return false;- /* Both the function and context data should match. */
- return (match_ctx->func == res_ctx->func) && (match_ctx->ctx == res_ctx->ctx);
+}
+void kunit_defer_cancel(struct kunit *test,
kunit_defer_function_t func,void *ctx)+{
- struct kunit_defer_ctx defer_ctx;
- struct kunit_resource *res;
- defer_ctx.func = func;
- defer_ctx.ctx = ctx;
- res = kunit_find_resource(test, __kunit_defer_match, &defer_ctx);
- if (res) {
kunit_defer_cancel_token(test, res);kunit_put_resource(res);- }
+}
+void kunit_defer_trigger(struct kunit *test,
kunit_defer_function_t func,void *ctx)+{
- struct kunit_defer_ctx defer_ctx;
- struct kunit_resource *res;
- defer_ctx.func = func;
- defer_ctx.ctx = ctx;
- res = kunit_find_resource(test, __kunit_defer_match, &defer_ctx);
- if (res) {
kunit_defer_trigger_token(test, res);/* We have to put() this here, else free won't be called. */kunit_put_resource(res);- }
+}
I am not really sure if you must provide the 'tokenless' cancel or trigger APIs. They just feel a bit much to me. Well, if you have a reason to do so then this looks good to me.
Yours, -- Matti